'use strict'; const common = require('../common'); const assert = require('assert'); const dnsPromises = require('dns').promises; dnsPromises.lookupService('127.0.0.1', 22).then(common.mustCall((result) => { assert.strictEqual(result.service, 'ssh'); assert.strictEqual(typeof result.hostname, 'string'); assert.notStrictEqual(result.hostname.length, 0); })); // Use an IP from the RFC 5737 test range to cause an error. // Refs: https://tools.ietf.org/html/rfc5737 assert.rejects( () => dnsPromises.lookupService('192.0.2.1', 22), { code: /^(?:ENOTFOUND|EAI_AGAIN)$/ } );